An X-Y peripheral is characterized by X-Y movement of a workpiece relative to a tool to achieve a desired pattern thereon or record a desired pattern therefrom. Alternatively, the tool can be moved in an X-Y fashion relative to the workpiece. Exemplary X-Y peripherals are sewing machines, engravers, digitizers and pen platters.
Exemplary of current systems for controlling X-Y peripherals are the computer controlled sewing machine systems that employ an architecture whereby a single master controller manages a non-variable number of sewing machine heads. As a consequence of this, there are a plurality of computer controlled sewing machine systems. A consumer can therefore purchase a computer controlled sewing machine system that includes a master controller and a sufficient number of sewing machine heads to satisfy his current production requirements. For example, a consumer with relatively small production requirements can purchase a computer controlled sewing machine that employs a master controller and a single sewing machine head. In contrast, a high volume operation would most likely purchase a computer controlled sewing machine system that has, perhaps, four or more sewing machine heads controlled by a master controller. However, such computer controlled sewing machine systems have several drawbacks. For instance, such systems do not address the future production requirements of the consumer in the most efficient manner. For example, if the consumer's production requirements at the time of purchase dictated a computer controlled sewing machine system having a master controller and two sewing machine heads, but production requirements had increased to the point where a three head system was required then the consumer has, as of the present, two possible options. First, the consumer can purchase another computer controlled sewing machine system having a controller and a single sewing machine head. In this scenario, the consumer whose production requirements necessitated the addition of a single head now has two heads and two controllers. Thus, the consumer has been placed in the position of having to purchase, due to the current architectures, an additional controller. A further disadvantage of such a configuration is that it requires either two operators, one to interface with each controller, or a single operator multiplexing his time between each controller. Second, the consumer can trade in his two head system at, most likely, a discount from the original purchase price, for a three head system. While the consumer now possesses a system comprised of the minimum number of components to satisfy his new requirements, i.e. three heads and a controller, he has lost the difference between the original purchase price for the two head system and the trade in or resale price. Alternatively, the consumer could initially purchase a three head system thereby anticipating an increase in future production requirements. In this instance the consumer must suffer the initial cost of a three head system when only a two head system is required. Consequently, the consumer is placed in the position of having to purchase unnecessary equipment. The present architecture also has several inefficiencies or disadvantages when viewed from the manufacturers perspective. Specifically, each new computer controlled sewing machine system necessitates additional research and development, production and maintenance costs. For example, if a manufacturer produces a two head system and wishes to offer to a three head system he, most likely, must suffer the research and development costs of upgrading the two head hardware and software to accommodate the additional head, the cost of a new production line, and the expense of maintaining two systems, i.e. the two head system and three head system. Consequently, the present architecture employed in systems for controlling X-Y peripherals lacks the flexibility to meet the necessarily unpredictable future production requirements of the consumer. Further, due to this lack of flexibility, there are unnecessary costs and inefficiencies imposed on both the consumer and the manufacturer or producer of systems for controlling X-Y peripherals. Therefore, there exists a need for a system for controlling X-Y peripherals that is capable of meeting both the current and future production requirements of the consumer while minimizing the up-front or current cost thereof. Further, there is a need for a system for controlling X-Y peripherals that reduces the research and development, production and maintenance costs to the manufacturer.
The present architecture employed in systems for controlling X-Y peripherals, and computer controlled sewing machine systems in particular, does not discriminate between the individual heads. Consequently, the operation of any one head is dependent upon the operation of every other head in the system. Due to this lack of discrimination, each head in a multi-head configuration must perform the same function. Thus, production is dependent upon the architecture employed in the system rather than upon the requirements for the products being produced by the system. Hence, the heads in such systems cannot be utilized in their most cost effective or efficient manner. Similarly, if a single head needs to be idled for maintenance purposes or the like then, in a system employing the current architecture, all of the other heads must also be idled while the problem is corrected. Again, the throughput or production of the system is constrained by the current architecture employed in such systems. Specifically, the entire production of the system is idled due to a single head malfunction. Consequently, the non-malfunctioning heads are not used in the most time effective and, hence, cost effective manner. Therefore, there exists a need for a system for controlling X-Y peripherals that provides independent head control to increase the flexibility of the system and thereby allow each head and, hence, the system to be used in a more efficient and productive manner.
Presently, systems for controlling X-Y peripherals employ a controller to manage one type of X-Y peripheral. Exemplary of such a system is one that is comprised of a single controller and one or more sewing machines. Similarly, there are systems available for exclusively controlling other types of X-Y peripherals. For example, there are systems for exclusively controlling digitizers, engravers and plotters. Presently, however, a consumer must purchase a separate controller for each different type of X-Y peripheral that he wishes to utilize. For example, if a consumer desires or needs a sewing machine system and a engraving system then he must purchase both a sewing machine system having a controller with one or more sewing machine peripherals and a separate engraving system having another controller and one or more engravers. Consequently, the consumer must bear the cost of two controllers for managing two types of X-Y peripherals, the sewing machine and the engraver. Further, manufacturers of several types of X-Y peripherals are placed in the position of developing, producing and maintaining controllers for each different X-Y peripheral type. Thus, there exists the need for a controller that is capable of coordinating or managing a system comprised of one or more different types of X-Y peripherals, thus reducing costs to both the consumer and the manufacturer and further increasing the flexibility of a consumer's system.
Currently, "BARUDAN" manufactures a computer controlled sewing machine system comprised of a host computer or controller that transmits data files to one or more stand alone sewing machines. Since the sewing machine peripherals are stand alone machines, they are capable of sewing or embroidering without any communication from the host computer. Consequently, the sewing machine peripherals in such a system must, in and of themselves, include the hardware and software necessary to perform stitching or embroidering operations. Hence, the hardware and software necessary to stand alone operation is repeated in each sewing machine peripheral in such a system. The cost of the hardware and software necessary for the stand alone operation of each peripheral is, again, borne by the consumer of such systems. Further, data files containing stitching information are typically sent to the sewing machine peripherals in a compressed format thereby requiring an apparatus at each sewing machine peripheral to decompress the data. Thus, there exists the need for a computer controlled sewing machine system where the decompression and stand alone hardware and/or software necessary to the operation of the sewing machine peripherals is centrally located thereby eliminating the need for repeating such hardware and/or software in each sewing machine peripheral. Thus, the cost to the consumer and the cost of development, manufacturing and maintenance to the manufacturer can be further reduced.
It is also presently known that large computer systems employ a disk controller intermediate the main frame computer and the disk drives. The disk controller routes information from the main frame to the appropriate disk drive. Typically, the disk controller manages one or more strings of disk drive where each string is composed of a variable disk drives that may be in varying operational states.
An additional aspect of computer controlled X-Y peripherals is the servo control employed to control the head or tool of the X-Y peripheral. In particular, reciprocation of the needle or head in a computer controlled sewing machine requires both speed control and position control. Speed control is necessary to coordinate the reciprocation of the needle with the movement of the carriage to achieve the desired embroidery pattern. Position control, on the other hand, is required where a color change head is employed in the computer controlled sewing machine. A color change head allows the computer to change thread colors during the embroidering of a design or after the sewing of a first design but before the sewing or embroidering of a second design. Position control is necessary with color change heads because the head must be positioned within .+-.20/20 of top dead center in order to effect a color change. Further, various maintenance procedures also require that the head position be controlled. A presently known head servo system employs a stepper motor which provides good positioning ability, but exhibits poor speed or velocity control at high rpm's due to the torque/speed curves associated with stepper motors. Another system employs a unidirectional motor in conjunction with a brake and a clutch. This servo system provided good speed control, but position control is difficult due to the fact that the motor, the brake and the clutch each must be individually adjusted in order to achieve good positioning control. Consequently, there exists a need for a head servo control system that provides both speed and positioning control. Further, there is a need for a head servo control system that reduces the number of mechanical components and, hence, the number of control signals necessary to control each component.
Typically, computer controlled X-Y peripherals require a home or reference position from which movement of a carriage holding a workpiece can be coordinated. Movement of the carriage, and hence the workpiece, relative to a head or tool is used to produce a desired design on the workpiece. Conversely, the head or tool can be moved relative to the workpiece in order to achieve a pattern or design on the workpiece. As such, the carriage is placed at the home position prior to the execution of a design on the workpiece. It is also necessary to place the carriage at the home position when its current position is unknown. For example, at power up or following a power failure recovery. Typically, the computer controlled X-Y peripheral includes hardware and/or software to control the X-Y positioning and the velocity of the carriage relative to the home position. Further, such computer controlled X-Y peripherals also, typically, include a separate apparatus for positioning the carriage at the home position. If the standard X-Y positioning and velocity control apparatus could be adapted to move the carriage to home then the special home positioning apparatus employed in current computer controlled X-Y peripherals could be rendered unnecessary thereby reducing, among other things, the cost and complexity of the X-Y peripheral.